My point is that for most adults in the world right now (western, industrialized, developing, modern, whatever) there is an obesity epidemic and any amount of focused self-care through exercise and diet will improve health outcomes. Eat less, exercise more. If an arbitrary metric on fitness tracker helps you reach that goal, then just do it.
Weight loss doesn't automatically mean "healthier."
Using vo2 as a metric of "health" would not be correct if weight loss is the sole attribution of vo2 gain.
One can lose weight without doing a minute of exercise and vo2 would increase.
If one is interested in getting healthier, I think it's well worth the time to learn about how the metrics work.